Some architectural spaces feature grid ceiling systems, in which grid elements are placed within a space with a high ceiling, to create a feel of an upper boundary to the space, even though the actual ceiling is higher. For example, there may be a network of any kind of grid elements (e.g., pipes, tubes, slats, nets, webbing and the like) that crisscross the space, such that occupants of the space perceive the grid elements as an upper boundary. The grid elements are usually supported from a ceiling, but sometimes supported by walls or a floor. Providing light to spaces that feature grid ceiling systems presents unique challenges.